electric aeroplanes

This is a picture of an electric aeroplane that flies indoors on a wire. They are quite interesting to design.
This one is a bit more difficult, it can be adjusted to fly very slowly and yet remain very controllable

This one flies really really slowly at a high angle of attack and remains so stable it's weird but you have to make it out of foam insulating wallpaper (as far as I know) (unobtainium) (cf kites) (maybe there is some kind of synthetic unobtainium). In fact B&Q are selling it at the moment.

This is a pattern for making the propellors. Make them from bits of yoghurt pot, place the pattern on the pot obliquely so that the base of the blade (dotted line)conforms to the rim of the pot. Radius should be about 3.7 cm.
You can buy much more efficient ones for about 50 pence.
This is a pattern for making sycamores. Cut shape from thin card, tape to top of drinking straw, fold card to make curved profile, spin between palms of hands. Experiment with weighting rotor tips with double thickness of card. Span about 6".

This is an electric helicopter made from an LP cover
It's capable of hovering for a few seconds. It uses a high impedance motor driving a plastic gearwheel attached to the centre of the cardboard rotor with sticky-fixers.
It overcomes the reaction torque with four reaction vanes in the slipstream of the rotor, they are held on a cardboard support structure which is glued to the motor. The gearwheel runs on a setscrew which is also glued to the motor. The gearwheel + rotor can be removed by undoing the nut at the top.
There is a lot of scope for experiment, especially with the reaction vanes: would lots of small ones be better instead of four big ones, different angles of attack etc.similar thing on youtubemore examples on youtube